Rock City Rd over Rock Run CR
Stephenson County, Illinois · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Rock City Rd over Rock Run CR in Stephenson County, Illinois, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1965, making it 60 years old at the 2025 inventory.
- It carries about 725 vehicles a day (traffic count year 2024).
- Its listed owner is the county highway agency.
- It is one of 126 of the 340 inventoried bridges in Stephenson County rated fair (37.1%); 11 (3.2%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated October 2024, on a 24-month routine inspection cycle.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (42.42823, -89.4774)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Continuous concrete slab |
| Length | about 100 ft |
| Location | 3.0 Mi W Davis |
| NBI structure number | 089300200000000 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Illinois department of transportation.
Busiest bridges in Stephenson County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 20 EB over Sumner Creek | 1959 | 12,700 | Fair |
| US 20 WB over Wickham Creek | 1983 | 12,700 | Fair |
| US 20WB over Sumner Creek | 1994 | 12,700 | Good |
| US 20 EB over Wickham Creek | 1999 | 12,700 | Fair |
| US 20 & Private Rd over Silver Creek Trib | 1959 | 12,700 | Fair |
| Il 26 over Yellow Creek | 1988 | 12,600 | Fair |
All bridges nearby: Stephenson County, IL bridge conditions · every bridge in Stephenson County · Illinois bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.